Determination of daytime clenching events in subjects with and without self-reported clenching.
Fujisawa, M., Kanemura, K., Tanabe, N., Gohdo, Y., Watanabe, A., Iizuka, T., Sato, M. and Ishibashi, K. (2013), Determination of daytime clenching events in subjects with and without self-reported clenching. Journal of Oral Rehabilitation. doi: 10.1111/joor.12087
To confirm the validity of self-awareness of daytime clenching, specific electromyogram (EMG) characteristics of clenching behaviour were determined using surface EMG recordings. Temporal muscle EMGs were recorded for 5 h in 13 subjects with self-reported clenching (clenching group: 27·5 ± 3·8 years old) and 12 subjects without self-reported clenching (control group: 28·6 ± 7·1 years old). All EMG data were recorded and stored on a portable EMG apparatus. The device was similar in size to a hearing aid, and suitable to record daytime EMG without restriction of daily activities. A clenching event was defined as muscle activity exceeding 10% of the maximum voluntary contraction. Furthermore, simultaneous voice recording was also performed to identify the corresponding EMG event as functional or parafunctional. The mean number of clenching events was 192·8 ± 228·8 and 24·8 ± 26·5 in the clenching and the control groups, respectively (P < 0·05, Mann–Whitney U-test); the number of functional events was not significantly different between the groups. Because there was a significant difference in the number of clenching events between the groups, self-reported daytime clenching is considered to be a reliable screening parameter for awake bruxism.